2 <img src="media/microwatt-title.png" alt="Microwatt">
7 A tiny Open POWER ISA softcore written in VHDL 2008. It aims to be simple and easy
10 ## Simulation using ghdl
12 <img src="http://neuling.org/microwatt-micropython.gif" alt="MicroPython running on Microwatt"/>
15 You can try out Microwatt/Micropython without hardware by using the ghdl simulator. If you want to build directly for a hardware target board, see below.
17 - Build micropython. If you aren't building on a ppc64le box you
18 will need a cross compiler. If it isn't available on your distro
19 grab the powerpc64le-power8 toolchain from https://toolchains.bootlin.com
22 git clone https://github.com/mikey/micropython
30 - Microwatt uses ghdl for simulation. Either install this from your
31 distro or build it. Next build microwatt:
34 git clone https://github.com/antonblanchard/microwatt
39 - Link in the micropython image:
42 ln -s ../micropython/ports/powerpc/build/firmware.bin simple_ram_behavioural.bin
45 - Now run microwatt, sending debug output to /dev/null:
51 ## Synthesis on Xilinx FPGAs using Vivado
53 - Install Vivado (I'm using the free 2019.1 webpack edition).
58 source /opt/Xilinx/Vivado/2019.1/settings64.sh
64 pip3 install --user -U fusesoc
67 - Create a working directory and point FuseSoC at microwatt:
70 mkdir microwatt-fusesoc
72 fusesoc library add microwatt /path/to/microwatt/
75 - Build using FuseSoC. For hello world (Replace nexys_video with your FPGA board such as --target=arty_a7-100):
78 fusesoc run --target=nexys_video microwatt --memory_size=8192 --ram_init_file=/path/to/microwatt/fpga/hello_world.hex
80 You should then be able to see output via the serial port of the board (/dev/ttyUSB1, 115200 for example assuming standard clock speeds). There is a know bug where initial output may not be sent - try the reset (not programming button on your board if you don't see anything.
82 - To build micropython (currently requires 1MB of BRAM eg an Artix-7 A200):
85 fusesoc run --target=nexys_video microwatt
90 - A simple test suite containing random execution test cases and a couple of
91 micropython test cases can be run with:
99 This is functional, but very simple. We still have quite a lot to do:
101 - There are a few instructions still to be implemented
102 - Need to add caches and bypassing (in progress)
103 - Need to add supervisor state (in progress)